Projectile, Ammunition and Method of Manufacturing a Projectile

ABSTRACT

The present invention relates to a projectile, in particular a diabolo, for ammunition of a pneumatic weapon, a CO 2  weapon or a spring-loaded weapon, wherein the projectile is made of a mixture comprising metal and 2 to 15% by weight of plastic, based on the total weight of the projectile.

The present invention relates to a projectile, in particular a diabolo, for ammunition of a pneumatic weapon, a CO₂ weapon or a spring-loaded weapon. Further, the present invention provides ammunition for a pneumatic weapon, a CO₂ weapon or a spring-loaded weapon. Furthermore, the present invention relates to a method for manufacturing a projectile, in particular a diabolo, for ammunition of a pneumatic weapon, a CO₂ weapon or a spring-loaded weapon.

Air rifle pellets are made of lead as standard. However, due to the increasing demand for environmentally compatible projectile materials, the use of lead is becoming more and more unsuitable. Alternative materials, such as tin or zinc, have so far rarely been used for air rifle pellets because the materials are significantly more expensive than lead and also have a reduced density compared with lead, so that the air rifle pellets have reduced precision at longer distances. Furthermore, in the prior art, it is already occasionally known to use plastic for air rifle pellets. However, due to the low density of plastic, the plastic air rifle pellets have a poor precision. Furthermore, additional friction losses occur between the air rifle pellet and the barrel of the firearm, which in turn leads to a reduction in muzzle energy.

US 2018/0156588 A1 discloses an air rifle bullet made of a metal-elastomer mixture. US 2018/0156588 A1 pursues the objective of providing environmentally compatible air rifle bullets with the ability to be attracted by a magnet so that the air rifle bullets function in air rifles that depend on a magnet to hold the bullet in position before firing. However, precision as well as external ballistics of the projectile according to US 2018/0156588 A1 have proven to be disadvantageous.

It is an objective of the present invention to overcome the disadvantages of the prior art, in particular to provide a projectile for a pneumatic weapon, CO₂ weapon or spring-loaded weapon that has improved precision and/or ballistics.

The objective is solved by the object of claims 1, 9, 12 and 13, respectively.

Accordingly, a projectile, in particular a diabolo, is provided for ammunition of a pneumatic weapon, a CO₂ weapon or a spring-loaded weapon. In a pneumatic weapon, compressed air stored for firing is released via a valve system to drive the projectile. In a CO₂ weapon, for example, carbon dioxide is used. In a spring-loaded weapon, a spring-loaded piston is accelerated in a cylinder, whereby the piston generates an air cushion which drives the projectile.

The projectile is made from a mixture comprising metal and 2 to 15% by weight of plastic, based on the total weight of the projectile. According to an exemplary further development, the projectile is manufactured lead-free, i.e. without the addition of lead. It may be provided that the plastic used is capable of absorbing the metal content, in particular uniformly. Furthermore, the plastic may be selected such that good processing is possible and the plastic is not too brittle. It has been found according to the present invention that by means of the specific percentage by weight of 2 to 15% of plastic, an optimum of density, in particular high density, and ductility is achieved, whereby improved precision is achievable.

According to an exemplary further development, it is provided that the metal is only a single metal or a mixture of two or more different metals. Likewise, it may be provided that the plastic is merely a single plastic or a mixture of two or more plastics. Further, it may be provided that the mixture consists of the metal and plastic.

In a further exemplary further development of the projectile according to the invention, additives may be admixed or mixed with the mixture from which the projectile is made. For example, inorganic substances or materials, such as granite, sand, clay, cement, or ceramic sintered materials or the like, are possible. It has been found, particularly with regard to the weight and thus the precision of the projectile, that the additives should be present in a certain maximum percentage, in particular in such a way that the additives replace the metal in a percentage of 10% by weight at most.

In an exemplary embodiment, the metal (or the mixture of two or more metals) is present in the projectile in an amount of 85 to 98% by weight, in particular in an amount of 93 to 97% by weight, 94 to 96% by weight or of about 95% by weight, based on the total weight of the projectile. The presence of a high weight percentage of metal according to the invention increases the density of the projectile, which has a positive effect on precision.

It may be provided that the metal is selected from the group consisting of copper, iron, zinc, tin, magnesium, tungsten, cemented carbide, sintered metal, and mixtures thereof.

In an exemplary embodiment of the present invention, the metal in the projectile is in the form of particles. In this regard, it may be provided, for example, that the particles are spherical particles. In this context, a particle is considered spherical if the ratio of the smallest diameter of the particle to the largest diameter of the particle is from 0.8 to 1, preferably from 0.9 to 1, most preferably from 0.95 to 1. The particles of the metal are considered spherical as a whole if at least 90%, preferably 95%, most preferably at least 97%, most preferably at least 99% of the particles are spherical as defined above.

According to a further exemplary embodiment of the projectile according to the invention, the particles have an average diameter of 5 to 15 μm. Likewise, it may be provided that the particle diameters are in a range from 1 to 60 μm, preferably 3 to 45 μm. Hereby, it may be provided that at least 90% of the particles, more preferably at least 95% of the particles, more preferably at least 97%, most preferably at least 99% of the particles have a corresponding diameter. The diameter of the particles can be determined by means of transmission electron microscopy (TEM). For this purpose, an image generated by TEM of a sample of particles showing at least 100 particles can be evaluated by determining the diameter for the at least 100 particles. The diameter can be determined manually or with the aid of appropriate software. The diameter to be determined is the longest diameter of the article that is visible on the TEM image.

According to an exemplary further development of the present invention, the plastic is a thermoplastic elastomer. Surprisingly, it has been shown that the thermoplastic elastomer is capable of absorbing larger proportions of metal, in particular metal particles, such as metal powder, so that an overall higher density of the mixture of the projectile according to the invention is achieved, whereby its precision is improved. In alternative embodiments, the plastic may be a thermoplastic, an elastomer, or a thermoset. In terms of the present disclosure, an elastomer is a dimensionally stable but elastically deformable plastic. The elastomer can be elastically deformed by tensile and compressive loading. In terms of the present disclosure, a thermoplastic elastomer is a plastic that behaves similarly to another (non-thermoplastic) elastomer at room temperature, but can be plastically deformed when heat is applied. The elastomer (or the mixture of two or more different elastomers) is present in the mixture from which the projectile is formed in an amount of 2 to 15% by weight, in particular in an amount of 3 to 7% by weight, 4 to 6% by weight or about 5% by weight, based on the total weight of the projectile. Suitable alternative plastic materials are polyethylene (PE), thermoplastic polyurethane (TPU), polyamide, in particular polyamide 12 (PA12), or HTE, HFE.

According to an exemplary further development, the thermoplastic elastomer is natural rubber or an ethylene-alkyl acrylate copolymer, preferably an ethylene-alkyl acrylate copolymer. In this context, it may be provided that the alkyl group contained in the alkyl acrylate is C₁ to C₁₀ alkyl, preferably C₁ to C₆ alkyl, more preferably C₂ to C₅ alkyl, more preferably C₂ to C₄ alkyl. It is particularly preferred that the thermoplastic elastomer is ethylene-butyl acrylate copolymer.

In a further exemplary embodiment of the projectile according to the invention, the mixture has a density of 4 to 12 g/cm³, in particular of 4.5 to 7 g/cm³ or of 5 to 6 g/cm³. The density can be determined according to DIN EN ISO 1183-1 (in the form valid at the time of application). Compared to known projectiles made of metal-plastic mixtures, the projectile according to the invention has a significantly higher density while providing a desired ductility. As a result, the projectile according to the invention provides significantly improved precision.

In addition, it may be provided that the projectile has an elongation at break according to ASTM D638 (as in effect at the time of application) of 3% to 15%.

Similarly, it may be provided that the mixture has a melt flow index (260° C./5 kg) of 1.5 to 2.5, preferably about 2 g/10 min.

In a further exemplary embodiment of the projectile according to the invention, its surface is at least sectionwisely mechanically and/or chemically treated, in particular coated, in particular lacquered or electroplated.

According to another aspect of the present invention, which is combinable with the preceding aspects and exemplary embodiments, a projectile, in particular a diabolo, is provided for ammunition of a pneumatic weapon, a CO₂ weapon or a spring-loaded weapon.

The projectile is made from a mixture of metal and plastic, in particular a thermoplastic elastomer, formed by extrusion. The metal can, for example, be provided in powder form and/or the plastic in granulate form, whereby the metal powder and plastic granulate can be mixed to form a particularly homogeneous mixture.

The projectile comprises an injection point for the metal-plastic mixture, the surface of which is different from an adjacent surface of the projectile. The projectile according to the invention can therefore be manufactured by means of known injection molding tools and take advantage of the benefits of injection molding technology. The metal and/or the plastic, in particular the thermoplastic elastomer, may have one or more of the above properties. According to the present invention, the injection point may be referred to as the point on the projectile that is visible after removing the sprue formed on the projectile during injection molding of the mixture according to the invention. The sprue is generally, during injection molding, the part of the molded part which does not belong to the molded part and which is formed by the mixture melt guided in feed channels to the injection mold. The sprue can be removed by hand, for example, by knocking off or shearing or by other mechanical finishing. The result is an injection point visible on the projectile surface.

According to another aspect of the present invention, which is combinable with the preceding aspects and exemplary embodiments, ammunition is provided for a pneumatic weapon, a CO₂ weapon or a spring-loaded weapon comprising a projectile according to the invention.

According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, there is provided a method for manufacturing a projectile according to the invention, in particular a diabolo, for ammunition of a pneumatic weapon, a CO₂ weapon or a spring-loaded weapon.

According to the method, plastic granules, in particular granules of a thermoplastic elastomer, and metal powder are provided. The plastic granules and the metal powder are mixed and then introduced by extrusion into an injection mold forming the outer shape of the projectile. In the method, the injection pressure can be maintained until the mixture in the injection mold has cooled down and, in particular, solidified. Further, the injection mold may only be opened when the mixture has completely solidified and the projectile has been completely demolded.

Preferred embodiments are given in the dependent claims.

In the following, further characteristics, features and advantages of the invention will become clear by means of a description of preferred embodiments of the invention with reference to the accompanying exemplary drawings, in which show:

FIG. 1 a perspective view of an exemplary embodiment of a projectile according to the invention;

FIG. 2 a side view of the projectile of FIG. 1;

FIG. 3 a sectional view of the projectile according to FIGS. 1 and 2;

FIG. 4 a perspective view of an exemplary embodiment of a projectile according to the invention;

FIG. 5 a side view of the projectile of FIG. 4;

FIG. 6 a sectional view of the projectile according to FIGS. 4 and 5;

FIG. 7 a perspective view of an exemplary embodiment of a projectile according to the invention;

FIG. 8 a side view of the projectile of FIG. 7;

FIG. 9 a sectional view of the projectile according to FIGS. 7 and 8;

FIG. 10 a perspective view of an exemplary embodiment of a projectile according to the invention;

FIG. 11 a side view of the projectile of FIG. 10;

FIG. 12 a sectional view of the projectile according to FIGS. 10 and 11;

FIG. 13 a perspective view of an exemplary embodiment of a projectile according to the invention;

FIG. 14 a side view of the projectile of FIG. 13;

FIG. 15 a sectional view of the projectile according to FIGS. 13 and 14;

FIG. 16 a perspective view of an exemplary embodiment of a projectile according to the invention;

FIG. 17 a side view of the projectile of FIG. 16;

FIG. 18 a sectional view of the projectile according to FIGS. 16 and 17;

FIG. 19 a perspective view of an exemplary embodiment of a projectile according to the invention;

FIG. 20 a side view of the projectile of FIG. 19;

FIG. 21 a sectional view of the projectile according to FIGS. 19 and 20;

FIG. 22 a perspective view of an exemplary embodiment of a projectile according to the invention;

FIG. 23 a side view of the projectile of FIG. 22; and

FIG. 24 a sectional view of the projectile according to FIGS. 22 and 23.

In the following description of exemplary embodiments of projectiles according to the invention, a projectile according to the invention is generally indicated with the reference numeral 1. Identical or similar components are provided with identical or similar reference numerals. The projectiles 1 may be manufactured by the manufacturing method according to the invention. In the following description of the exemplary embodiments illustrated in the figures, it may be assumed that the projectile 1 is used for ammunition of a pneumatic weapon, a CO₂ weapon or a spring-loaded weapon. The projectiles 1 according to the invention may also be referred to as diabolo 1. The projectiles 1 according to the invention are made of a mixture comprising metal and 2-15% by weight of plastic, based on the total weight of the projectile. In particular, the plastic is a thermoplastic elastomer, although other plastic materials listed in the above description may alternatively be used.

FIGS. 1-3 show a first exemplary embodiment of a projectile 1 according to the invention, which is designed to be rotationally symmetrical with respect to a center or longitudinal axis M. FIGS. 1-3 show a so-called flat-head diabolo. The projectile 1 comprises a substantially truncated cone-shaped projectile tail 3, which tapers continuously in the direction of the projectile front or nose. Immediately adjoining the tail 3 is a substantially truncated cone-shaped projectile nose 5 which, starting from a transition 7 to the projectile tail 3, widens continuously before opening into a flat front face 9 to form a so-called flat head. The front face 9 is chamfered circumferentially in the direction of the front or nose 5 and forms a phase 13 inclined in the range from 30% to 60%. At the rear, the cone-shaped tail 3 opens into a cylinder tail section 15 which has an opening 19 at its tail-side end face 17. From the opening 19, a recess 21 extends in the axial direction into the projectile nose 5. An inner dimension of the recess 21 is essentially adapted to an outer dimension of the projectile tail 3. The recess 21 is also formed in a substantially frustoconical shape and tapers continuously in the direction of the projectile nose 5.

FIGS. 4-6 show a so-called round head (diabolo), which differs from the flat head diabolo 1 according to FIGS. 1-3 essentially by the curved front surface 23 on the nose side. The front surface 23 is convex or partially spherical in shape. A further difference is present with respect to the dimensioning of the recess 21. According to FIGS. 4-6, as shown in particular in FIG. 6, the recess does not extend in the axial direction as far as the projectile nose 5, but ends shortly before the transition 7 between the tail 3 and the nose 5. Furthermore, the recess 21 is formed in a stepwise frustoconical shape and forms a nose-sided tip 25 which lies on a central axis of the rotationally symmetrical projectile 1.

The projectile 1 according to FIGS. 7-9 is a so-called pointed-head diabolo, which is generally larger in the axial direction, i.e. longitudinal extension direction of the projectile 1, than the flat-head diabolo or the round-head diabolo. This is related in particular to the dimensioning of the nose 5. Starting from a narrow cylinder section 27 in the region of the projectile nose 5, an end face 29 pointing in the direction of the front extends in the shape of a cone or pyramid. The axial dimensioning of the conical or pyramidal nose 29 is about ⅓ of the total axial dimensioning of the projectile 1. In FIG. 9 it can be seen that the recess 21 corresponds essentially to the recess 21 according to FIGS. 1-3. In contrast to the preceding embodiments, the projectile nose widens much faster than in FIGS. 1-6. This means that a tail-side circumferential outer surface 31 of the projectile nose 5 is oriented at a steeper angle with respect to the central axis M than the corresponding projectile nose outer surfaces 31 according to FIGS. 1-6.

FIGS. 10-12 illustrate a further embodiment of a projectile 1 according to the invention, in which the projectile 1 is realized as a hollow-point diabolo. In order to avoid repetition, only the differences with respect to the preceding embodiments will be discussed below. The difference lies essentially in the design of the projectile nose 5. Starting from the section 27, the projectile nose 5 tapers continuously, substantially analogously to the pointed-head diabolo according to FIGS. 7-9, with the circumferential nose end face 33 terminating circumferentially in an annular end edge 35 which bounds a nose-side opening 37. A depression 39 extends from the opening 37 in the direction of the tail 3 in the manner of a blind hole and ends approximately at the axial height of the cylinder section 27. This means that a recess base 41 is formed approximately at the level of the cylinder section 27, which is oriented substantially perpendicular to the longitudinal extension direction of the projectile 1. The recess base 41 merges into a circumferential recess wall 43, which in turn opens into the end face edge 35.

FIGS. 13-15 illustrate a diabolo projectile 1 having a nose-side spherical core 45, substantially half of which is received in a nose-side recess 47 formed in the projectile nose 5 and shaped substantially complementary to an outer surface of the spherical core 45. The core may be made of plastic or metal, for example, and/or may be press-fitted or glued into the recess 47.

In contrast to the previous embodiments, the tail-side recess 21 extends only about ⅓ of the total longitudinal extent of the projectile 1. A front-side recess base 49 of the recess 21 is located at a clear distance from the transition 7 between the tail 3 and the nose 5.

FIGS. 16 to 18 show an exemplary embodiment of the projectile 1 according to the invention. The projectile 1 is again essentially made of solid material from the mixture of metal and plastic according to the invention. The tail 3 has a significantly shorter dimension compared to the previous embodiments, with the axial dimensioning of the tail 3 corresponding to approximately ¼ of the overall axial dimensioning of the projectile 1. A significant difference from the previous embodiments lies in the design of the nose 5. Starting from the transition 7, a truncated cone section formed essentially of solid material is formed with an increasing outer diameter, the inclination of the outer nose surface 51 being significantly lower with respect to the central axis M than in the previous embodiments. Adjacent to the cylinder section 27 on the nose side is a dome-like end surface 53, which is present substantially circumferentially with respect to the central axis M and is continuously convex in shape. The rear-side recess 21 extends in the axial direction and substantially around the full axial dimension of the rear end 3. In particular, a recess bottom 49 is located substantially at the level of the transition 60.

In the embodiment according to FIGS. 19-21, a so-called piercing diabolo 1 is shown, the tail 3 of which, including the rear recess 21, is formed according to the embodiment according to FIGS. 4-6. The difference lies in particular in the dimensioning of the nose, in particular its front side. The nose 5 is formed in a fundamentally similar manner to the nose 5 of FIGS. 10-12. In contrast to FIGS. 10-12, the piercing diabolo 1 according to FIGS. 19-21 has a conical tip made in one piece with the projectile 1, coaxial with respect to the central axis M, extending in the axial direction and protruding from the nose-side recess by about ⅔ of its total axial extension. On the nose side, the tip 55 has a rounded nose 57. In this respect, there is an annular space 59 surrounding the tip 55, which has a substantially V-shaped cross-section.

With reference to FIGS. 22-24, another exemplary embodiment of a projectile 1 according to the invention is shown. The projectile 1 is shaped substantially analogously to the flat-head diabolo 1 according to FIGS. 1-3. In contrast to FIGS. 1-3, the projectile 1 has, in the region of the projectile tail 3, a plurality of circumferentially uniformly distributed longitudinal grooves 59 which are formed substantially around the full axial extent of the tail and open into the transition 7 at the front. The longitudinal grooves may, for example, have a V-shaped cross-section. Due to the cylinder-like tapering dimensions of the projectile tail 3, the longitudinal grooves 59 increasingly merge on the nose side. Overall, the result is a corrugated or serrated surface in the circumferential direction of the projectile 1.

The features disclosed in the foregoing description, figures, and claims may be significant, both individually and in any combination, for the realization of the invention in the various embodiments.

REFERENCE LIST

1 Projectile

3 Tail

5 Nose

7 Transition

11 Face

13 Phase

15 Cylinder section

17 Face

19 Opening

21 Depression

23 Curved face

25 Tip

27 Cylinder section

29 Conical nose section

31 Truncated cone nose section

33 Conical nose section

35 Front rim

37 Opening

39 Depression

41 Depression ground

43 Depression wall

45 Core

47 Concave recess

49 Recess ground

51 Nose outer surface

53 Convex curved end face

55 Tip

57 Nose

59 Annular space

61 Longitudinal groove

M Center axis 

1. A projectile, for ammunition of a pneumatic weapon, a CO2 weapon or a spring-loaded weapon, wherein the projectile is made of a mixture comprising metal and 2 to 15% by weight of plastic, based on the total weight of the projectile.
 2. The projectile according to claim 1, wherein the metal is contained in the projectile in an amount of 85 to 98% by weight, based on the total weight of the projectile.
 3. The projectile of claim 1, wherein the metal is selected from the group consisting of copper, iron, zinc, tin, magnesium, tungsten, cemented carbide, sintered metal, and mixtures thereof.
 4. The projectile according to claim 1, wherein the metal in the projectile is in the form of particles.
 5. The projectile according to claim 4, wherein the particles have an average diameter of 5 to 15 μm.
 6. The projectile according to claim 1, wherein the plastic is a thermoplastic elastomer.
 7. The projectile according to claim 6, wherein the thermoplastic elastomer is natural rubber or an ethylene alkyl acrylate copolymer, preferably ethylene butyl acrylate copolymer.
 8. The projectile according to claim 1, wherein the mixture has a density of 4 to 12 g/cm3.
 9. A projectile for ammunition of a pneumatic weapon, a CO2 weapon or a spring-loaded weapon, wherein the projectile is made of a mixture of metal and plastic formed by means of extrusion and has an injection point for the metal-plastic mixture, the surface of which differs from an adjacent surface of the projectile.
 10. The projectile according to claim 9, comprising a tail provided with the injection point, wherein in particular the injection point surface differs from an adjacent surface of the projectile at least in the region of the tail.
 11. The projectile according to claim 9, the surface of which is mechanically and/or chemically treated at least sectionwisely, in particular coated, in particular lacquered or electroplated.
 12. Ammunition for a pneumatic weapon, a CO2 weapon or a spring-loaded weapon, comprising a projectile according to claim
 1. 13. Method for manufacturing a projectile for ammunition of a pneumatic weapon, a CO2 weapon or a spring-loaded weapon, in which plastic granules and metal powder are provided, the plastic granules and the metal powder are mixed and then introduced by means of extrusion into an injection mold forming the outer shape of the projectile.
 14. The method according to claim 13, wherein the plastic granules and the metal powder are mixed to provide a mixture comprising metal and 2 to 15% by weight of plastic, based on the total weight of the projectile. 